Which department should an Australian husband go to if he refuses to pay alimony?

In the implementation of child support, the Australian Department of Humanitarian Services provides a service to collect child support on behalf of one spouse after the termination of the relationship. When one party refuses to perform its obligations within the time limit, the Ministry of Social Security may issue a restraining order to the border management department until it pays off the arrears. The Ministry of Social Security has the right to issue this administrative order directly without applying to the court.